org.h2.index

类 DualIndex

java.lang.Object

org.h2.engine.DbObject

org.h2.schema.SchemaObject

org.h2.index.Index

org.h2.index.VirtualTableIndex

org.h2.index.DualIndex

所有已实现的接口:

HasSQL

public class DualIndex
extends VirtualTableIndex

An index for the DUAL table.

字段概要

从类继承的字段 org.h2.index.Index

columnIds, columns, indexColumns, indexType, table, uniqueColumnColumn

从类继承的字段 org.h2.engine.DbObject

AGGREGATE, comment, COMMENT, CONSTANT, CONSTRAINT, database, DOMAIN, FUNCTION_ALIAS, INDEX, RIGHT, ROLE, SCHEMA, SEQUENCE, SETTING, SYNONYM, TABLE_OR_VIEW, trace, TRIGGER, USER

从接口继承的字段 org.h2.util.HasSQL

ADD_PLAN_INFORMATION, DEFAULT_SQL_FLAGS, NO_CASTS, QUOTE_ONLY_WHEN_REQUIRED, REPLACE_LOBS_FOR_TRACE, TRACE_SQL_FLAGS

构造器概要

构造器

构造器和说明
DualIndex(DualTable table)

方法概要

限定符和类型	方法和说明
boolean	canGetFirstOrLast() Check if the index can directly look up the lowest or highest value of a column.
Cursor	find(SessionLocal session, SearchRow first, SearchRow last) Find a row or a list of rows and create a cursor to iterate over the result.
Cursor	findFirstOrLast(SessionLocal session, boolean first) Find the first (or last) value of this index.
double	getCost(SessionLocal session, int[] masks, TableFilter[] filters, int filter, SortOrder sortOrder, AllColumnsForPlan allColumnsSet) Estimate the cost to search for rows given the search mask.
String	getCreateSQL() Construct the CREATE ...
String	getPlanSQL() Get the message to show in a EXPLAIN statement.

从类继承的方法 org.h2.index.VirtualTableIndex

add, checkRename, close, getRowCount, getRowCountApproximation, needRebuild, remove, remove, truncate

从类继承的方法 org.h2.index.Index

canFindNext, canScan, checkIndexColumnTypes, compareRows, findNext, getColumnIndex, getColumns, getCostRangeIndex, getCreateSQLForCopy, getDiskSpaceUsed, getDuplicateKeyException, getDuplicatePrimaryKeyMessage, getIndexColumns, getIndexType, getRow, getRowFactory, getTable, getType, getUniqueColumnCount, getUniqueRowFactory, isFindUsingFullTableScan, isFirstColumn, isHidden, isRowIdIndex, mayHaveNullDuplicates, removeChildrenAndResources, update

从类继承的方法 org.h2.schema.SchemaObject

getSchema, getSQL, getSQL

从类继承的方法 org.h2.engine.DbObject

getChildren, getComment, getCreateSQLForMeta, getDatabase, getDropSQL, getId, getModificationId, getName, invalidate, isTemporary, isValid, rename, setComment, setModified, setObjectName, setTemporary, toString

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

从接口继承的方法 org.h2.util.HasSQL

getTraceSQL

构造器详细资料

DualIndex

public DualIndex(DualTable table)

方法详细资料

find

public Cursor find(SessionLocal session,
                   SearchRow first,
                   SearchRow last)

从类复制的说明: Index

Find a row or a list of rows and create a cursor to iterate over the result.

指定者:

find 在类中 Index

参数:

session - the session

first - the first row, or null for no limit

last - the last row, or null for no limit

返回:

the cursor to iterate over the results

getCost

public double getCost(SessionLocal session,
                      int[] masks,
                      TableFilter[] filters,
                      int filter,
                      SortOrder sortOrder,
                      AllColumnsForPlan allColumnsSet)

从类复制的说明: Index

Estimate the cost to search for rows given the search mask. There is one element per column in the search mask. For possible search masks, see IndexCondition.

指定者:

getCost 在类中 Index

参数:

session - the session

masks - per-column comparison bit masks, null means 'always false', see constants in IndexCondition

filters - all joined table filters

filter - the current table filter index

sortOrder - the sort order

allColumnsSet - the set of all columns

返回:

the estimated cost

getCreateSQL

public String getCreateSQL()

从类复制的说明: DbObject

Construct the CREATE ... SQL statement for this object.

覆盖:

getCreateSQL 在类中 Index

返回:

the SQL statement

canGetFirstOrLast

public boolean canGetFirstOrLast()

从类复制的说明: Index

Check if the index can directly look up the lowest or highest value of a column.

覆盖:

canGetFirstOrLast 在类中 Index

返回:

true if it can

findFirstOrLast

public Cursor findFirstOrLast(SessionLocal session,
                              boolean first)

从类复制的说明: Index

Find the first (or last) value of this index. The cursor returned is positioned on the correct row, or on null if no row has been found.

覆盖:

findFirstOrLast 在类中 Index

参数:

session - the session

first - true if the first (lowest for ascending indexes) or last value should be returned

返回:

a cursor (never null)

getPlanSQL

public String getPlanSQL()

从类复制的说明: Index

Get the message to show in a EXPLAIN statement.

覆盖:

getPlanSQL 在类中 Index

返回:

the plan